Field emission from carbon nanosheets on pyramidal Si(100)

Carbon nanosheets were synthesized on pyramidal Si(100) substrates without any catalyst in a microwave plasma-enhanced chemical vapour deposition process. The average length and the growth time of carbon nanosheets were measured to be ∼300 nm and 10 min, equivalent to a growth rate of ∼30 nm min-1. By replacing flat Si(100) with pyramidal Si(100) as the substrate, the field emission performance of carbon nanosheets was greatly improved. A low turn-on field of 3.2 V μm-1 and a high current density of 2.5 mA cm-2 at 7.0 V μm-1, close to those of carbon nanotube emitters, were achieved. The improvement in field emission was attributed primarily to the pyramidal shape